Wheelchair Drive System Over half of the wheelchair user population has developed upper extremity (UE) pain and injury. One of the activities that likely contribute to the development of injury is wheelchair propulsion. A number of technologies have been developed to address this issue including ergonomic pushrims, geared hub wheels, lever drives and pushrim-activated power assist wheels. While the non-powered technologies have been shown to incrementally reduce demand on the UE, power assist wheels can practically eliminate the demand. However, it is not reasonable to use power assist wheels when powered off due to their considerable weight. In essence, they are powered wheelchairs with pushrim-mounted joysticks. There is a need to develop a light-weight removable power drive system for a manual wheelchair that can be used selectively by the individual to reduce UE demand during the course of everyday propulsion activities. This project will develop a wheelchair drive system to meet this need and evaluate its efficacy through a series of focus group assessments and a long-term use study. As a result of this project, wheelchair users will gain access to technology that will reduce UE demand and hopefully reduce their risk of developing overuse injuries. PUBLIC HEALTH RELEVANCE: Wheelchair Drive System Relevance to Public Health Manual wheelchair users are at considerable risk of developing upper limb overuse injuries. One preventative measure is to reduce demand on the upper extremities during propulsion. This project will develop a lightweight removable drive system that can be used to provide propulsion assistance, thereby reducing physical demand and the likelihood of developing overuse injuries.